• Journal of Radiation Protection and Research
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• v.27 no.1
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• pp.1-10
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• 2002

High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of as low as reasonably achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons. This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients ate treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Palo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions $30cm{\times}30cm{\times}20cm$. the anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is transected into transverse 36 slices of 2.5cm thickness. Photon dose was measured using a Capintec PR-06C ionization chamber with Capintec 192 electrometer (Capintec Inc., Ramsey, NJ), TLD( VICTOREEN 5000. LiF) and film dosimetry V-Omat, Kodak). In case of fetus, the dosimeter was placed at a depth of loom in this phantom at 100cm source to axis distance and located centrally 15cm from the inferior edge of the $30cm{\times}30cm^2$ x-ray beam irradiating the Rando phantom chest wall. A acryl bridge of size $40cm{\times}40cm^2$ and a clear space of about 20 cm was fabricated and placed on top of the rectangular polystyrene phantom representing the abdomen of the patient. The leaf pot for testicle shielding was made as various shape, sizes, thickness and supporting stand. The scattered photon with and without shielding were measured at the representative position of the fetus and testicle. Measurement of radiation scattered dose outside fields and critical organs, like fetus position and testicle region, from chest or pelvic irradiation by large fie]d of high energy radiation beam was performed using an ionization chamber and film dosimetry. The scattered doses outside field were measured 5 - 10% of maximum doses in fields and exponentially decrease from field margins. The scattered photon dose received the fetus and testicle from thorax field irradiation was measured about 1 mGy/Gy of photon treatment dose. Shielding construction to reduce this scattered dose was investigated using lead sheet and blocks. Lead pot shield for testicle reduced the scatter dose under 10 mGy when photon beam of 60 Gy was irradiated in abdomen region. The scattered photon dose is reduced when the lead shield was used while the no significant reduction of scattered photon dose was observed and 2-3 mm lead sheets refuted the skin dose under 80% and almost electron contamination. The results indicate that it was possible to improve shielding to reduce scattered photon for fetus and testicle when a young patients were treated with a high energy photon beam.

• Journal of the Korea Organic Resources Recycling Association
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• v.6 no.1
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• pp.75-85
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• 1998

Algal meal (cell) was produced from the solution of dairy cow wastes by fermentation of ulothrix. sp. and chlorella sp. Raw wastes mainly feces were diluted with ground water to give dry matter concentration of 0.5 w/v of wastes in 20 l amounts of ten plastic containers. Each containers were covered with plastic nets and vinyl films to protect from the insects and rain. Algea cells were harvested every 3 to 5 days and dried by sunlight and artifitial heat. Dried cells were ground by a feed meal, and analyzed and tested for the chemical composition of dry cell, in vitro DM and protein digestibility and the safty of algae. Protein contents in algae meals, ulothrix (29.37%) and chlorella (29.24%) were similar. However, chlorella contained lower Neutral detergent fiber (5.92%) than ulothrix(20,76%), and higher ash (32.86%) and calcium (12.62%) than ulothrix (28.66% and 6.09%) (P<.01). Ulothrix protein had higher for essential amino acids; valine, isoleucine and phenylalanine, than chlorella (P<.05). Algal fats contained high saturated fatty acids, C16:0 and C18:0, for ulothrix and high unsaturated fatty acids, C18:1 and C18:2, for chlorella (P<.01). In vitro digestibility of. ulothrix tended to be higher for DM, but lower for protein than chlorella. The weight gain and survival percentage were higher for pond fishes (loaches, Misgurnus sp. ) fed diet added chlorella meal than diets added ulothrix meal and control diet (P<.05).

• SUVANNABHUMI
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• v.3 no.1
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• pp.47-66
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• 2011

Malay society is rooted on the Islamic concept. That Islam influenced every corner of that Malay society which had ever been an edge of the civilizations of the Indus and Ganges. Once the letters of that Hindu religion namely Sanscrit was adopted to this Malay society for the purpose of getting the Malay language, that is, Bahasa Melayu down to the practical literation but in vain. The Sanscrit was too complicated for Malay society to imitate and put it into practice in everyday life because it was totally different type of letters which has many of the similar allographs for a sound. In the end Malay society gave it up and just used the Malay language without using any letters for herself. After a few centuries Islam entered this Malay society with taking Arabic letters. It was not merely influencing Malay cultures, but to the religious life according to wide spread of that Islam. Finally Arabic letters was to the very means that Malay language was written by. It means that Arabic letters had been used for Arabic language in former times, but it became a similar form of letters for a new language which was named as Malay language. This Arabic letters for Arabic language has no problems whereas Arabic letters for Malay language has some of it. Naturally speaking, arabic letters was not designed for any other language but just for Arabic language itself. On account of this, there occurred a few problems in writing Malay consonants, just like p, ng, g, c, ny and v. These 6 letters could never be written down in Arabic letters. Those 6 ones were never known before in trying to pronounce by Arab people. Therefore, Malay society had only to modify a few new forms of letters for these 6 letters which had frequently been found in their own Malay sounds. As a result, pa was derived from fa, nga was derived from ain, ga was derived from kaf, ca was derived from jim, nya was derived from tha or ba, and va was derived from wau itself. Where must these 6 newly modified letters be put on this Arabic keyboard? This is the very core of this working paper. As a matter of course, these 6 letters were put on the place where 6 Arabic signs which were scarecely written in Malay language. Those 6 are found when they are used only in the 'shift-key-using-letters.' These newly designed 6 letters were put instead of the original places of fatha, kasra, damma, sukun, tanween and so on. The main differences between the 2 set of 6 letters are this: 6 in Arabic orginal keyboard are only signs for Arabic letters, on the other hand 6 Malay's are real letters. In others words, 6 newly modified Malay letters were substituted for unused 6 Arabic signs in Malay keyboard. This type of newly designed Malay Jawi Script keyboard is still used in Malaysia, Brunei and some other Malay countries. But this sort of keyboard also needs to go forward to find out another way of keyboard system which is in accordance with the alphabetically ordered keyboard system. It means that alif is going to be typed for A key, and zai shall be typed when Z key is pressed. This keyboard system is called 'Malay Jawi-English Rumi matching keyboard system', even though this system should probably be inconvenient for Malay Jawi experts who are good at Arabic 'alif-ba-ta'order.